Kim Young-Min, Lee Kwang-Su, Kim Won-Mun, Kim Min, Park Han-Oh, Choi Chang Won, Han Joong-Soo, Park Shin-Young, Lee Ki-Sung
Department of Biology and Medicinal Science, Pai Chai University, Daejeon, Republic of Korea.
New Drug R&D Center, Bioneer Corporation, Daejeon, Republic of Korea.
Mol Cell Toxicol. 2022;18(2):267-276. doi: 10.1007/s13273-022-00221-5. Epub 2022 Jan 18.
Bacterial ghosts (BGs) are empty cell envelopes commonly generated using Gram-negative bacteria; they represent a potential platform for efficient adjuvant and vaccine delivery systems. However, the efficient production of BGs from bacteria in a short period of time is challenging.
The purpose of this study was to investigate the possibility of producing BGs in the Gram-positive using various chemicals, and the potential application of BGs as a novel immunomodulatory agent.
In this study, ghosts (BSGs) were generated, for the first time to the best of our knowledge, using the minimum inhibitory concentration (MIC) of hydrochloric acid (HCl; 6.25 mg/mL), sulfuric acid (HSO; 3.125 mg/mL), and nitric acid (HNO; 6.25 mg/mL). Among the BSGs generated using these chemicals, HCl-induced BSGs were completely DNA-free as confirmed by real-time polymerase chain reaction. Scanning electron microscopy showed the formation of transmembrane lysis tunnel structures in HCl-induced BSGs. Murine macrophages exposed to the HCl-induced BSGs at a concentration of 1 × 10 CFU/mL showed a cell viability of 97.8%. Additionally, HCl-induced BSGs upregulated the expression of pro-inflammatory cytokines including interleukin (IL)-1β, tumor necrosis factor alpha, and IL-6. Furthermore, we found differences in the protein expression profiles between intact live bacteria and BSGs using two-dimensional electrophoresis coupled with peptide mass fingerprinting/matrix-assisted laser desorption/ionization-time of flight mass spectrometry analysis.
These data suggest that the HCl-induced BSGs may be potentially safe and effective candidates for inactivated bacterial vaccines and/or immunostimulants.
The online version contains supplementary material available at 10.1007/s13273-022-00221-5.
细菌幽灵（BGs）是空的细胞包膜，通常利用革兰氏阴性菌产生；它们代表了高效佐剂和疫苗递送系统的一个潜在平台。然而，在短时间内从细菌高效生产BGs具有挑战性。
本研究的目的是探讨使用各种化学物质在革兰氏阳性菌中产生BGs的可能性，以及BGs作为新型免疫调节剂的潜在应用。
在本研究中，据我们所知首次使用盐酸（HCl；6.25mg/mL）、硫酸（H₂SO₄；3.125mg/mL）和硝酸（HNO₃；6.25mg/mL）的最低抑菌浓度（MIC）产生了芽孢杆菌属细菌幽灵（BSGs）。在使用这些化学物质产生的BSGs中，实时聚合酶链反应证实，HCl诱导的BSGs完全无DNA。扫描电子显微镜显示HCl诱导的BSGs中形成了跨膜裂解隧道结构。暴露于浓度为1×10⁶CFU/mL的HCl诱导的BSGs的小鼠巨噬细胞显示细胞活力为97.8%。此外，HCl诱导的BSGs上调了包括白细胞介素（IL）-1β、肿瘤坏死因子α和IL-6在内的促炎细胞因子的表达。此外，我们使用二维电泳结合肽质量指纹图谱/基质辅助激光解吸/电离飞行时间质谱分析，发现完整活细菌和BSGs之间的蛋白质表达谱存在差异。
这些数据表明，HCl诱导的BSGs可能是灭活细菌疫苗和/或免疫刺激剂的潜在安全有效的候选物。
在线版本包含可在10.1007/s13273-022-00221-5获取的补充材料。
